We once suggested to a client that the goal of advertising should be to get consumers to do something -- anything -- in response to the ad they have just seen. The marketing director said disparagingly, "We don't do direct-response TV."

He clearly was imagining an over-the-top pitch that would drive customers to buy right then and there. But making a purchase is just one action we want from a consumer. After seeing an ad, someone might type in a URL, pass the ad on, join a Facebook page, scan a QR code, send an SMS and so on.

In a digital environment, where you can give the consumer the option of participating in your message on his own terms, the traditional model of advertising from Madmen days -- Awareness, Interest, Desire, then Action -- is getting flipped on its head.

If you can motivate a viewer to become a participant, several psychological effects will kick in to make the message more powerful:

• Autonomy. Participating consumers are less likely to feel that the message has been forced upon them. This can circumvent their resistance and enhance motivation. Grey , New York's, "the Story Beyond the Still" campaign for Cannon had contestants shoot and edit short films to continue the narrative of a feature that the brand itself had created. The campaign inspired millions to participate.
• Discovery: When consumers come to a realization through activity, the information will feel more salient and real. SCVNGR had visitors to Buffalo Wild Wings compete in challenges on smartphones for instantly redeemable prizes. The campaign resulted in nearly 200,000 unique players competing in more than 1.3 million challenges that were often recorded and broadcast to the players' social-media profile pages, leading others to discover the brand.
• Personal relevance: As consumers participate, they can in effect change the message to suit themselves; this then feels more interesting, consequential and relevant. Google Creative Labs partnered with the band Arcade Fire to create a truly intimate and interactive music-video viewing experience. Through a clever combination of Google technologies (Google Chrome, Maps and Street View), the setting of the video became the streets of the viewer's hometown.
• Cognitive dissonance: People strive to have their thoughts, feelings and actions aligned. As consumers take action, the likelihood increases that they will change their thoughts and feelings to go along with the action. At Naked, we created a campaign called Rename Speed, to get drivers to slow down on country roads. We asked people to join in the cause for a small rural town to change its name from Speed to SpeedKills. We found that after passing the message on, "liking" the campaign on Facebook or contributing to the cause in some way, people were motivated to start slowing down themselves.

At some point soon, nearly all good communications will be "action" communications. If you can get a consumer to interact with your message, and this makes your message more effective, then why wouldn't you?

The shift will demand that clients, agencies and research companies release their "muscle memory" and change the way they develop strategies, create communication and evaluate results. It will require a combined understanding of human motivation and behavior, and of how to apply technology to ensure that what you are asking consumers to do is easy enough and possible.

The old marketing model is on the way out, but the road ahead can be circuitous and filled with pitfalls if you don't understand the why and the how.